The present invention relates, in general, to a dispenser for fluids and in the disclosed embodiment the dispenser is for dispensing glue material such as cynoacrylate glue. More particularly, this invention pertains to a non-drip dispenser especially useful for dispensing low viscosity materials.
There are certain problems associated with the dispensing of liquid materials such as a cynocrylate glue. For one thing, the material that is being dispensed tends to drip after a certain amount has been dispensed because the viscosity of the material may be very low say on the order of 1-2000 centipoise. When the material is thinned and of a water consistency, it is quite apt to flow out of the dispenser after a certain amount has been dispensed.
Another problem associated with some prior art dispensers is that they employ metal holders and the threads on the dispenser become bonded by the material that is to be dispensed therefore possibly making the dispenser inoperative. This problem is sometimes only overcome by substituting a different material such as polypropolene or polyvinyl chloride.
The prior art devices quite consistently teach the use of a reservoir for holding a predetermined amount of the material that is to be dispensed. See, for example, U.S. Pat. Nos. 2,529,937 and 2,823,953. One of the problems with this arrangement is that any material that is purchased must be transferred from the manufacturers shipping bottle to the dispensing device. This makes for a time consuming operation and there is a possibility of loss of some of the material. Also, if one attempts to apply a negative pressure or vacuum to the reservoir there is a possibility of sucking the material out of the reservoir and into the vacuum equipment. This, of course, is quite undesirable.
Accordingly, one object of the present invention is to provide an improved dispenser particularly adapted for use with a low viscosity liquid material.
Another object of the present invention is to provide a non-drip dispenser for a watery-like substance.
A further object of the present invention is to provide a fluid dispenser that directly accommodates the manufacturers shipping bottle thereby eliminating the need for a transfer of the liquid from the bottle to a reservoir of the dispensing unit.
Still another object of the present invention is to provide a fluid dispenser including a valve means or trigger means which is usable by an operator of the device to meter relatively precise amounts of the fluid which is being dispensed.
Still a further object of the present invention is to provide a non-drip dispenser wherein the material that is being dispensed is maintained in its original bottle and there is no possibility of communication of the material to other parts of the device such as the air lines.